Microsoft researcher Don Syme talks about the development of the functional language F#.
He says Haskell (and Python) has been a huge influence on the development of F#. The F# lightweight syntax was also inspired by Haskell and Python. He also says there have been some mistakes along the way. "Some experimental features have been removed as we're bringing F# up to product quality, and we've also made important cleanups to the language and library. These changes have been very welcomed by the F# community."

it connects directly to .NET. Lack of GUI support is a notorious weakness of functional languages. F# may be the first to be usable as part of a large GUI program without a slow, kludgy C interface to connect it.

Another interesting functional language is Scala, which runs on the JVM. It is no problem to use Java classes from Scala, thus you can use Swing to write GUIs. There is also a good book about Scala: Programming in Scala.

I looked at both Scala and F# (but I did not code anything with them yet) and I think Scala is a bit nicer then F#.